The DLC, the short form of Differential Leukocyte Count is a measurement of the percentage of different WBC types in the blood. With the help of the DLC test we come to know about the presence of immature WBCs. Their presence...
Introduction
The DLC, the short form of Differential Leukocyte Count is a measurement of the percentage of different WBC types in the blood. With the help of the DLC test we come to know about the presence of immature WBCs. Their presence is responsible for conditions like anemia, leukemia, and infections.
WBCs or leukocytes are blood cells that are an integral part of our immune system. Hence, the DLC test or the differential Leukocyte test detects the percentage of different WBC types in the blood.
On the other hand, the TLC (Total Leukocyte Count) test investigates the total number of WBCs or leukocytes in our body. So, the TLC DLC test probes the WBC credentials in our blood.
Understanding the blood function
Our blood, which runs through the veins, arteries, and capillaries, comprises 55% plasma and 45% of blood cells. The blood constitutes blood plasma and blood cells— RBC (red blood cells) aka erythrocytes, —WBC (white blood cells) aka leukocytes, and platelets or thrombocytes.
The blood performs the following functions:
- It carries oxygen and nutrients to the lungs and other organs in the body
- It helps in clots when an injury strikes so that there is prevention of blood loss
- Blood transports cells and antibodies to combat infections within the body
- Blood carries impurities to the kidneys and liver to clean and filter the waste
- It regulates body temperature
So, the blood and its components must be in their ideal reference ranges to carry out the above-mentioned essential body functions seamlessly.
Under what circumstances a DLC test is ordered?
The DLC in a blood test that is ordered by a doctor in any of the following conditions:
- It is ordered during the Complete Blood Count (CBC) test when someone goes for a regular health check-up
- Combined TLC and DLC tests are done when the doctor wants to investigate the condition of the internal infection
- It is conducted as a follow-up test when the CBC outcomes are abnormal
- It is done to help in detecting infections and inflammations
- A DLC test helps in detecting conditions with low WBC counts like blood disorders, and bone marrow diseases
- It helps in keeping a tab on bone marrow functions
- It also helps in monitoring cancer treatment and chemotherapy
Different types of leukocytes during a DLC test
WBCs, which are a type of blood cells, are manufactured in the bone marrow and they are present in the blood and lymph system. WBCs help and boost the immune system in fighting against infections.
There are mainly five major types of WBC:
Neutrophils: They are the commonest WBC type, which helps in killing microorganisms or pathogens responsible for infections in the body.
Lymphocytes: Lymphocytes are divided into three types— B-cells, T-cells, and Natural Killer Cells. The B-cells, with the help of antibodies, function to annihilate the pathogenic viruses and bacteria within the body. T-cells crush those cells of the body that are infected by pathogens or tumor cells. Lastly, Natural killer cells destroy all the foreign cells marked by antibodies as cancer cells or infected cells by phagocytosis.
Monocytes: These cells create a defensive system against pathogens and attack them.
Eosinophils: These cells assist in fighting inflammation, infections, and allergies.
Basophils: They act as a defense by producing enzymes crucial to fight allergic reactions and asthma.
Interpretation of the result of the TLC, DLC Tests
It is very important to know the DLC normal value to rule out any conditions in the body.
There could be a variation in the normal differential WBC counts, as they could be governed by age, health, gender, and other external factors. There is increased production of WBC in the bone marrow due to an infection, inflammation, or cancer. The increased WBCs then combine to target and battle the condition.
Relative to the condition one or more WBC types stay elevated in the blood. So, when the condition improves or the infection heals or subsides, there is less production of WBC production in the bone marrow, and there is a depletion of WBC count in the blood.
The following are the normal ranges of DLC in adults:
WBC Type Reference range levels in percentage
- Neutrophils or Polymorphs - 40 to 60%
- Monocytes 2 to 8%
- Lymphocytes (B and T cells) 20 to 40%
- Basophils 0.5 to 1%
- Eosinophils 1 to4%
When there are increased counts of one or more WBC types it is a sign to become alert, because it is a warning of any infection or chronic condition, which has to be attended to immediately. It is important to note that even an increase or decrease in DLC is an indication of a possibility of health conditions. It could be a concern of the immune system, autoimmune disorders, and cancers where the body attacks the cells of the immune system.
The total Leukocyte count (TLC) should be 4000 to 11,000 cells/ cubic millimeter of blood, which is considered the normal range. There is a decrease in total WBC count or leukopenia when the body is unable to fight infections and diseases, making it prone to health problems.
This condition becomes palpable when a patient is undergoing chemotherapy treatment, suffering from influenza, malaria, tuberculosis, typhoid, and dengue.
A higher total WBC count or TLC level is called leukocytosis. People who are infected chronically can have inflammations, rheumatoid arthritis, connective tissue disorders, leukemia, and blood disorders.
The TLC-DLC test is not capable to detect a particular condition but it works as an important indicator when the body is plagued by an infection, inflammation, or a severe ailment. A TLC-DLC test may also suggest taking other subsequent tests to diagnose a specific condition or it may help in formulating any treatment plan.
Conclusion
WBCs comprise our blood cells, which help in the combat against infection, inflammation, or chronic condition in the body. We have seen that there are five different types of WBC types present in the blood and the DLC or the differential blood count test provides us a measure in percentage of each WBC type, while also aiding in disclosing the abnormal conditions of the body, predicting reduced immunity. TLC, or total leukocyte count, provides the overall measure of WBCs in the blood.
Hence, it is imperative that we understand the importance of an early or regular TLC- DLC testing. It will help in early detection of any acute condition, eventually contributing to initiating early treatment and prognosis.
FAQs
Are the DLC and WBC similar?
WBC (White blood cells) or leukocytes are the type of blood cells that help the immune system in defending against infectious pathogens or foreign bodies. While on the other hand, DLC (differential Leukocyte count) is the percentage count of different leukocytes or WBCs in the blood.
What is the normal range of DLC?
Refer to the following to know the normal range of the DLC blood test:
- Neutrophils – 2500-8000 per mm3 (55-70%)
- Monocytes – 100-700 per mm3 (2–8%)
- Lymphocytes – 1000-4000 per mm3 (20–40%)
- Basophils – 25-100 per mm3 (0.5-1%)
- Eosinophils – 50-500 per mm3 (1–4%)
What does it mean when DLC is high?
When the results are in the blood DLC test, the diagnosis may point towards a probable infection, inflammation, cancer, or any other ailment the body is battling against.
Can there be a variation in DLC test results based on different factors?
Yes, DLC test results can have variations, due to various factors like gender, age, the time of the test, etc. All these factors can impact the blood cells in the body, leading to a slight variation in DLC test results. On the other hand, taking certain medications can also alter the results. For people taking medicines like corticosteroids or chemotherapy drugs can influence WBC counts. So, it is important to refer to the results looking at the individual case.
